The present disclosure relates generally to rotary tools such as rotary grinders for grinding or shredding material, such as waste material. Waste material such as trees, brush, stumps, pallets, railroad ties, peat moss, paper, wet organic materials and the like are often processed with hammermill machines that generally fall into one of two categories: grinders or shredders. Grinders typically function by forcing the material into contact with a rotating member such as a drum having cutters at the outer diameter. The cutters of grinders travel at a relatively high rate of speed, typically exceeding 5000 feet per minute. Shredders typically function by forcing the material into contact with a rotating drum with cutters at the outer diameter. The cutters of shredders travel at a relatively low rate of speed, typically less than 500 feet per minute.
In both types of hammermill machines, the cutters are subjected to extreme loads. Although the loading differs, due to the differing speeds, the cutters must be securely attached to the rotating member. Further, the cutters in either machine can experience high rates of wear, particularly if the waste material is abrasive. For this reason the cutters are typically replaceable.
Improvements in rotary tools are desired.